Abstract: The anatomy Structure of the stem of Bougainvillea glabra was studied through the use of paraffin section method. The results revealed that the structure of the stem is composed of epidermis, cortex and vascular cylinder. The vascular bundles in the cortex are arranged in a circle. The other vascular bundles are arranged irregularly in the basic tissues. Within the structure, there are no pith rays, and the pith not obvious. The vascular bundle cambium is not observed and the growth of stem is not obvious, either. The vascular bundles are external phloem vascular bundles in large quantities. Such a structure renders it a strong transportation ability and resistant capability against drought to a certain extent. However, the cold-tolerance of Bougainvillea glabra is rather weak.